DRA: ResourceClaim Support for Workloads

<!-- This section is incredibly important for producing high-quality, user-focused documentation such as release notes or a development roadmap. It should be possible to collect this information before implementation begins, in order to avoid requiring implementors to split their attention between writing release notes and implementing the feature itself. KEP editors and SIG Docs should help to ensure that the tone and content of the Summary section is useful for a wide audience. A good summary is probably at least a paragraph in length. --> This enhancement describes additions to the [Workload API][KEP-4671] and [PodGroup API][KEP-5832] which make it possible to associate ResourceClaims and ResourceClaimTemplates with those objects to better facilitate sharing DRA resources between the Pods they contain. A ResourceClaim referenced by a PodGroup will be reserved for that PodGroup as a whole instead of its individual Pods, addressing the limit on the number of entries in a ResourceClaim's status.reservedFor list. A ResourceClaimTemplate referenced by a PodGroup will cause a ResourceClaim to be generated once for that PodGroup, like how ResourceClaimTemplates work today when referenced by a Pod. Whereas ResourceClaims today can only be shared between Pods by name, this will allow ResourceClaims to be shared by Pods in the same PodGroup where the exact name of the ResourceClaim is not known ahead of time.